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Publication numberUS5006969 A
Publication typeGrant
Application numberUS 07/430,619
Publication dateApr 9, 1991
Filing dateOct 31, 1989
Priority dateOct 31, 1989
Fee statusLapsed
Publication number07430619, 430619, US 5006969 A, US 5006969A, US-A-5006969, US5006969 A, US5006969A
InventorsLarry Lai
Original AssigneePlum Industrial Co., Ltd.
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Flashlight with end cap switch
US 5006969 A
A flash-light has a light-shell, a cylinder, a bottom cover which can be screwed to touch the bottom side of the cylinder, thus, the circuit of the bulb can be easily controlled.
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What is claimed is:
1. A flashlight comprising a conductive cylinder for receiving at least one dry cell, a mount at one end of the cylinder for a light bulb, said one end of the cylinder having an external thread, an internally threaded light-bulb shell for threading on said external thread, said cylinder having an opposite end with an internal thread, a non-conductive whorl ring with an outer thread to fit said internal thread, the whorl ring carrying an axially extending spiral spring for electrically contacting a dry cell in the casing, and a conducting cover on a rearward end of the whorl ring for selectively engaging and disengaging the casing by inwardly and outwardly threading the whorl ring on said internal thread thereby selectively completing and breaking a circuit containing the light bulb and dry cell so as to activate and deactivate the light bulb.
2. The invention defined in claim 1, wherein the whorl ring has a forward end with a screw-in plug, said spring extending through a bore in the plug, and wherein a padding ring having an external diameter corresponding substantially to an internal diameter of the casing is carried on the plug for use on an undersized cry cell to snugly accommodate same in the casing.
3. The invention defined in claim 2 which includes a replacement light bulb contained in said bore, said spring surrounding the replacement light bulb.

The conventional flashlights are installed with dry cells in the cylinder, and using their rotative bottom cap to link both the positive pole and negative pole of the cell to the bulb. Thus, with a switch in one of the poles, the on-and-off function can be controlled. Besides, while the cylinder diameter is fixed, it can only use the proper dry cells, otherwise it does not work.


The object of this invention is to provide a new structure and to use the rotative bottom cap to control the cell current.

The other object of this invention is to provide a flashlight which can suit more than two kinds of dry cells.

Another object of this invention is to provide a flashlight, which has a spare bulb that can be replaced when the original one fails.

The structure includes a cylinder, a light-shell, and a bottom cover. The light-shell links with the front end of the cylinder, the rear end meets the rotative bottom cap. By rotating the bottom cap, the cell current can be controlled.


This invention will now be described in detail with reference to accompanying drawings wherein:

FIG. 1 is an exploded perspective view of the flash-light of the present invention;

FIG. 2 is a cross-sectional view of taken along line 2--2 of FIG. 4;

FIG. 3 is an enlarged view of the portion 2 in FIG. 2;

FIG. 4 is an outer view of the present invention;

FIG. 5 and FIG. 5A are views similar to FIG. 2 showing smaller cells which replace the original cells in FIG. 2;

FIG. 6 is an enlarged view of the portion 6 in FIG. 5.


Referring to FIG. 1, the flashlight in accordance with the present invention includes a cylinder 1. It has outer threads 11 on the top for the light-shell. It also has inner threads 12 for the bulb 21. When the bulb 21 screws in, it makes contact with one end of the cell 3. For proof against water, after bulb 21 screw-in, a concave groove 13 with a leakage-proof rubber ring 14 tightly engages the light-shell. Thus, no water can infiltrate.

Cylinder 1 is for the dry cells 3. The inner thread 15 in its rear end matches the thread 42 of the bottom cover 4.

Light-shell 2 engages the outer thread 11 on cylinder 1 with its inner threads 24. The light-shell 2 has a light condenser 22, which can properly reflect all the light from the bulb and concentrate same. The limpid glass 23 can resist any infiltration.

The rear cover 4 consists of the cap 41, whorl ring 42, spring 43 and inner plug 44. The cap 41 is made of conductive material, with a whorl 42 stuck inside. The circular whorl 42 is made of non-conductive material, such as plastic, with a metal padding ring 45 in its end. The outer thread 421 on whorl 42 is for threading in the inner thread 15. The whorl 42 itself has a concave groove 422, for the leakage-proof rubber ring 46. It has also inner thread 423 to match the inner plug 44, and a spring 43. The spring 43 is made of conductive material, while the non-conductive inner plug 44 has a hole for the spare bulb 21, and its outer part matches padding ring 47. The outer diameter of the non-conductive padding ring 47 is the same as the inner diameter of cylinder 1.

Referring to FIGS. 2 and 3, the inner thread 12 in the top of cylinder 1 is for bulb 21. The outer thread 11 is for light-shell 2 and the dry cells 3 are placed in cylinder 1. Cap 41 and whorl 42 are stuck together, while the whorl 42 has a spring 43 and a spare bulb 21, screwed together by inner plug 44. The spring 43 is pyramidic in shape. One of its end touches the metal padding ring 45, while the other end touches the dry cell through the hole of inner plug 44. Therefore, one pole of the cell 3 links to the cover 41, as shown in FIGS. 2, 3 and 4. While the cap 41 is apart from cylinder 1, no current can reach bulb 21. If the cap 41 is tightly screwed, forming a circuit, the bulb 21 lights.

Referring to FIGS. 5, 6 and 7, when dry cells differ in their diameter and length, pug the padding ring 47 on the cell 3, screw in the inner plug 44, the spring 43 can extend, and touch the bottom of the cell, the circuit is completed. Therefore, using the screw of the cap 41, the circuit is freely controlled.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US3201542 *Jul 23, 1963Aug 17, 1965Homer T HutchisonMagnetic mechanical switch
US4819141 *Apr 27, 1987Apr 4, 1989Mag Instrument, Inc.Flashlight
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US5122938 *Feb 8, 1991Jun 16, 1992Pastusek Michael JTwist switch for flashlight
US5167447 *Apr 22, 1992Dec 1, 1992Gonzales Luis J MFlashlight using different size batteries
US5203624 *May 7, 1992Apr 20, 1993G.A. Thompson Company, Inc.Hazard warning device
US5287257 *Feb 8, 1993Feb 15, 1994G. A. Thompson Company, Inc.Hazard warning device
US5345370 *Dec 8, 1992Sep 6, 1994Satelight Technologies, Inc.Lamp or flashlight having a multi-feature rotating switching assembly
US5386352 *Jul 8, 1993Jan 31, 1995Chu; An G.Flashlight
US6092910 *Apr 29, 1999Jul 25, 2000Sung; RickFlashlight
US6208262 *Jun 1, 1999Mar 27, 2001Msx, Inc.Floor condition sensor
US6726342Nov 26, 2002Apr 27, 2004Plum Industrial Co., Ltd.Flashlight
US6851828Jul 15, 2003Feb 8, 2005William J. HansenFlashlight utilizing differently sized batteries
US7264372 *Mar 16, 2004Sep 4, 2007Mag Instrument, Inc.Apparatus and method for aligning a substantial point source of light with a reflector feature
US8727561 *Mar 17, 2011May 20, 2014Streamlight, Inc.Light and/or device having a compartment accommodating batteries of different types, sizes and/or shapes
US20120236551 *Mar 17, 2011Sep 20, 2012Sharrah Raymond LLight having a compartment accommodating batteries of different types, sizes and/or shapes
CN100587314CDec 3, 2004Feb 3, 2010永备电池有限公司Flashlight capable of operating with alternative size batteries
CN102593890A *Jan 17, 2012Jul 18, 2012广州广日电气设备有限公司Energy-saving self-powered system and manufacturing method thereof
CN102593890BJan 17, 2012Oct 22, 2014广州广日电气设备有限公司节能自供电系统及其制造方法
EP1605200A1 *May 20, 2005Dec 14, 2005Mellert SLT GmbH & Co. KGPenlight
WO2004083715A1 *Feb 25, 2004Sep 30, 2004Keith Joseph BorgLighting device restraint
WO2005057081A1 *Dec 3, 2004Jun 23, 2005Eveready Battery IncFlashlight that can operate with alternative size batteries
U.S. Classification362/206, 362/207
International ClassificationF21L4/00, F21V23/04
Cooperative ClassificationF21L4/005, F21V23/0421
European ClassificationF21V23/04L2, F21L4/00P
Legal Events
Jun 3, 2003FPExpired due to failure to pay maintenance fee
Effective date: 20030409
Apr 9, 2003LAPSLapse for failure to pay maintenance fees
Oct 23, 2002REMIMaintenance fee reminder mailed
Jul 2, 1998FPAYFee payment
Year of fee payment: 8
Sep 23, 1994FPAYFee payment
Year of fee payment: 4
Aug 13, 1990ASAssignment
Effective date: 19900605